[WedAssembly] Add -s and -S alias for --strip-all and --strip-debug

[ruiu]

LGTM

[kristina]

Closed by rL345767. Please mention the new revision or add "Differential Revision: rLXXXXXX" to the commit message so the commit is linked to the differential. Thanks.

test/wasm/strip-all.test

 RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
-RUN: wasm-ld --strip-debug -o %t.wasm %t.start.o
+RUN: wasm-ld --strip-all -o %t.wasm %t.start.o
+RUN: obj2yaml %t.wasm | FileCheck %s
+
+# Test alias -s
+RUN: wasm-ld -s -o %t.wasm %t.start.o
 RUN: obj2yaml %t.wasm | FileCheck %s
 
 # Check that there is no name section
 CHECK-NOT:   Name:    name

test/wasm/strip-debug.test

 RUN: llc -filetype=obj %p/Inputs/start.ll -o %t.start.o
 RUN: wasm-ld --strip-debug -o %t.wasm %t.start.o
 RUN: obj2yaml %t.wasm | FileCheck %s
 
+# Test alias -S
+RUN: wasm-ld -S -o %t.wasm %t.start.o
+RUN: obj2yaml %t.wasm | FileCheck %s
+
 # Check that there is no name section
 CHECK-NOT:   Name:    name

wasm/Options.td

 
 // Aliases
 def: JoinedOrSeparate<["-"], "e">, Alias<entry>;
 def: J<"entry=">, Alias<entry>;
 def: Flag<["-"], "E">, Alias<export_dynamic>, HelpText<"Alias for --export-dynamic">;
 def: Flag<["-"], "i">, Alias<initial_memory>;
 def: Flag<["-"], "m">, Alias<max_memory>;
 def: Flag<["-"], "r">, Alias<relocatable>;
+def: Flag<["-"], "s">, Alias<strip_all>, HelpText<"Alias for --strip-all">;
+def: Flag<["-"], "S">, Alias<strip_debug>, HelpText<"Alias for --strip-debug">;
 def: JoinedOrSeparate<["-"], "u">, Alias<undefined>;
 
 // LTO-related options.
 def lto_O: J<"lto-O">, MetaVarName<"<opt-level>">,
   HelpText<"Optimization level for LTO">;
 def lto_partitions: J<"lto-partitions=">,
   HelpText<"Number of LTO codegen partitions">;
 def disable_verify: F<"disable-verify">;
 def save_temps: F<"save-temps">;
 def thinlto_cache_dir: J<"thinlto-cache-dir=">,
   HelpText<"Path to ThinLTO cached object file directory">;
 defm thinlto_cache_policy: Eq<"thinlto-cache-policy", "Pruning policy for the ThinLTO cache">;
 def thinlto_jobs: J<"thinlto-jobs=">, HelpText<"Number of ThinLTO jobs">;